The Department of Pediatrics, Baylor College of Medicine, has participated in cooperative cancer study group activities (Southwest Cancer Chemotherapy Study Group, Southwest Oncology Group, Pediatric Oncology Group) for 26 years. The basic purpose of the group has been to search for better methods of treatment by which to cure or control cancer in children. As a result of these activities, more than 50% of the children with cancer can now be expected to survive their disease. In the evolutionary development of these groups, increasing emphasis has been placed upon coordinating multidisciplinary care and on expanding fundamental knowledge of cancer biology and pathophysiology. Essential information on the natural history of specific disease entities has provided important knowledge of prognostic factors that are critical elements of modern experimental design. Biostatistical involvement has become as essential part of the integrated programs that now include equal participation by the medical oncology, surgery, pathology, and radiotherapy disciplines. This project will continue this highly successful process.